This article at the New Yorker by Jeremy Miller notes that the threats to California's water are still many and varied. This article highlights the importance of continuing to be vigilant in watching over our water resources.
But this article also highlights the dangers of drought mismanagement: the systemic depletion of groundwater through unsustainable withdrawals, primarily for agriculture. As the CWSC noted in its first paper on the Water Security Challenge, one impact of drought is the depletion of aquifers to meet basic subsistence needs and then the collapse of the physical structure of the aquifer after the water is gone. Think an underground sinkhole, where once the water has been depleted, the aquifer compacts the ground and becomes less capable of holding water.
So, while California may have a lot of surface water—almost too much in some places—the ability of the land to absorb that water and the resilience of the earth in the next drought is in question.
Recharging aquifers may be a solution, insofar as it can help to replenish those aquifers that have not collapsed completely from the desiccation of the past decade of drought. However, California must ensure that its groundwater is properly regulated and overseen before the next drought. Otherwise, the resilience of California’s land might be tested to the breaking point.
UPDATE: The drought emergency was declared officially over by Governor Jerry Brown. Some restrictions will remain in place, but the full scale of conservation for the future is not yet known.